A supplement to R01 GM 75091 "Theoretical Population Genetics" is sought. This will allow the addition of the involvement of Dr. Sharon R. Browning of the University of Auckland, New Zealand. Dr Browning will extend the multi-locus work of this project to association mapping for human disease genes, using the technique of whole-genome association. This addresses a timely and practical need and it extends the theoretical development in the original project by drawing on the expertise of Sharon Browning in markov chain and other probabilistic modelling tools as well as computational strategies. The proposed work will be based on Sharon Browning's recent sue of variable length Markov chains to define localized haplotype structures. It therefore automatically adjusts to linkage disequilibrium structure and avoids ad-hoc windowing strategies.